The present invention relates to computer control systems and, more particularly, to a memory protection arrangement for such systems.
With the advent of the microprocessor chip as a relatively inexpensive control element, many types of systems are provided wherein the operation of the apparatus is controlled by such a microprocessor under the direction of applied software. A critical element in such a system is a memory unit in which operating parameters are stored. It is essential that that memory be protected during power-up and power-down situations. To the end of maintaining the energization of the memory unit, there has been provided, heretofore, various schemes for utilizing a back-up battery. These previous schemes have involved complex circuitry for accomplishing the transfer. While some of those schemes have been successfully effective for the intended purpose, their complexity has made them less than totally satisfactory.